1. Field of the Invention
The present invention relates to a method and apparatus for producing a roll photo film. More particularly, the present invention relates to a method and apparatus for producing a roll photo film in a manner with heightened precision and efficiency.
2. Description Related to the Prior Art
There are 120 and 220 types of roll photo film. The roll photo film includes a spool, a photo filmstrip and a light-shielding sheet. The spool consists of a cylindrical core and a pair of disk-shaped flanges formed on respective ends of the core. The light-shielding sheet is connected to the photo filmstrip, and wound therewith about the photo filmstrip to protect the photo filmstrip from ambient light. To load a camera with the roll photo film of 120 or 220 type, a rear end of the light-shielding sheet with an obliquely reduced width is inserted in a slit of a camera spool, before a few turns of the light-shielding sheet with the photo filmstrip is wound about the camera spool with the light-shielding sheet kept tightened without being unwound. This is an extremely difficult operation in setting the roll photo film in the camera.
The spool has a slit formed therein for receiving insertion of the front end portion of the light-shielding sheet. To facilitate a loading operation of the camera with the roll photo film of 120 or 220 type, the light-shielding sheet of the roll photo film is provided with a retaining hole, formed in its rear end, for retention to a retaining claw of the camera spool. Inside the slit of the spool, there are formed push ridges formed therewith for preventing the light-shielding sheet from being removed.
If conventional techniques are used for producing the light-shielding sheet, the retaining hole is formed by punching after the trimming operation of a front end portion of the light-shielding sheet. However there occurs a problem in that a position of the retaining hole is likely to irregular relative to a shape of outer edges of the front end portion, due to deviations in conveying the light-shielding sheet or deviations in a position to stop the light-shielding sheet. If the retaining hole is excessively deviated, the light-shielding sheet must be bent or distorted before the retaining hole can be engaged with the retainer claw. In case the retaining hole is engageable with the retainer claw, the engagement is likely to be incomplete and unreliable.
In forming the retaining hole, punched dust is created. If the punched dust should not be removed from the punching station in the course of operation, the punched dust is likely to remain on the light-shielding sheet when wound about the spool. The punched dust is so small in the size, and difficult to discover in inspection after the manufacture. Once the roll photo film with the punched dust is purchased by a user, the punched dust is likely to lie on an exposure region of the photo filmstrip inside the camera to lower an image quality of a photograph, or cause damages to the camera. There are a black paper type and a white paper type of the light-shielding sheet. The black paper type consists of paper material and carbon mixed therewith and having black color to shield light. The white paper type consists of paper material and a light-shielding layer of a coating applied thereon. The white paper type has a characteristic of being charged electrically with ease. A serious problem arises in that the punched dust is typically likely to remain with the white paper type of the light-shielding sheet.
In view of the foregoing problems, an object of the present invention is to provide a method and apparatus for producing a roll photo film, in which a retaining hole can be cut precisely and exactly through a light-shielding sheet to be wound with a photo filmstrip.
Another object of the present invention is to provide a method and apparatus for producing a roll photo film, in which a front end of a light-shielding sheet can be inserted reliably into a slit of a spool.
A further object of the present invention is to provide a method and apparatus for producing a roll photo film, in which inconsistency between parts constituting a roll photo film, if there is any, can be detected in the course of manufacture.
Another object of the present invention is to provide a method and apparatus for producing a roll photo film, in which an adhesive tape can be attached between a photo filmstrip and a light-shielding sheet with heightened precision.
Still another object of the present invention is to provide a method and apparatus for producing a roll photo film, in which a photo filmstrip or a light-shielding sheet, during operation of rotating a spool, can be wound about the spool without scratches or other failure.
Another object of the present invention is to provide a method and apparatus for producing a roll photo film, in which a trailer sheet and a leader sheet are included in a roll photo film with a photo filmstrip, and the photo filmstrip can be wound unfailingly with the trailer sheet and the leader sheet.
In order to achieve the above and other objects and advantages of this invention, a roll photo film includes a spool having a cylindrical core, a light-shielding sheet having a front end portion and a rear end portion, the front end portion being secured to the core, and a photo filmstrip, a first end of the photo filmstrip being secured to one securing position on the light-shielding sheet, the photo filmstrip being wound about the core in a roll form with the light-shielding sheet. In a roll photo film producing apparatus, a punch/die set includes a trimming punch and a trimming die, for trimming the rear end portion with a reduced width. A hole-forming punch and a hole-forming die are incorporated in the punch/die set, for cutting a-retaining hole through the rear end portion in a substantially simultaneous manner with trimming of the rear end portion.
The retaining hole is adapted to retention of the light-shielding sheet to a second spool after exposing the photo filmstrip, the second spool includes a second cylindrical core, a slit formed in the second core in an axial direction, and a retainer claw disposed in the slit, and the retaining hole is engaged with the retainer claw before the photo filmstrip and the light-shielding sheet are wound about the second core.
Accordingly the retaining hole can be cut precisely and exactly through the light-shielding sheet to be wound with the photo filmstrip.
In a preferred embodiment, a spool has a cylindrical core and a slit formed to extend in an axial direction thereof, the slit having first and second inner faces, there being a push claw disposed on the first inner face, a light-shielding sheet having a front end portion and a rear end portion, the front end portion being inserted in the slit and retained by the push claw. In the roll photo film producing apparatus, a position setter unit rotationally sets the core in a predetermined rotational position before winding the photo filmstrip about the core, to orient the slit in one direction. An inserter unit inserts the front end portion in the slit, wherein the position setter unit and the inserter unit are so preset as to direct the front end portion of the light-shielding sheet to the second inner face at an angle of 5-200xc2x0 therebetween. A rotating unit rotates the core to wind the photo-filmstrip about the core.
Furthermore, an inserter unit inserts the front end portion in the slit and for curving the light-shielding sheet away from the push claw while the front end portion is inserted.
Accordingly the front end-of the light-shielding sheet can be inserted reliably into the slit of the spool.
In another preferred embodiment for producing a roll photo film, a photo filmstrip of a predetermined length is formed by cutting continuous photo film. A light-shielding sheet of a predetermined length is formed by cutting continuous light-shielding sheet. One end of the photo filmstrip is secured to one securing position on the light-shielding sheet. A front end of the light-shielding sheet is secured to a core of a spool. The photo filmstrip and the light-shielding sheet are wound about the core in a roll form to obtain the roll photo film. In the roll photo film producing apparatus, a side printer unit is supplied with the continuous photo film, for effecting side-printing to the continuous photo film in accordance with predetermined photo film information and predetermined manufacture information being input, wherein the predetermined photo film information includes at least one of the predetermined length, sensitivity and a type of the photo filmstrip, and the predetermined manufacture information includes a number of a lot for producing the photo filmstrip. A tape attacher unit attaches an adhesive tape to the one end of the photo filmstrip, the adhesive tape having the predetermined photo film information printed thereon, and being adapted to attaching the photo filmstrip to the light-shielding sheet. A trimmer unit subjects the continuous light-shielding sheet to trimming of an outer edge of the light-shielding sheet, the continuous light-shielding sheet having the predetermined photo film information printed thereon. A seal attacher unit attaches an auxiliary seal to the continuous light-shielding sheet, the auxiliary seal having the predetermined photo film information printed thereon, and being located near to the front end portion of the light-shielding sheet, the auxiliary seal, when the photo filmstrip and the light-shielding sheet are wound about another spool after exposing the photo filmstrip, being wound about a roll of the photo filmstrip and the light-shielding sheet, to avoid unwinding the roll. A character printer unit prints the predetermined manufacture information to a closing seal in a written manner, the closing seal having the predetermined photo film information previously printed thereon. A seal winder unit winds the closing seal about the roll form of the photo filmstrip and the light-shielding sheet on the core, to avoid unwinding the roll form. First to fourth reader units respectively reads first photo film information from the light-shielding sheet, second photo film information from the adhesive tape, third photo film information from the closing seal, and fourth photo film information from the auxiliary seal. A checker unit checks coincidence between the predetermined photo film information and at least part of the first to fourth photo film information, the roll photo film being determined unacceptable if the at least part of the first to fourth photo film information is detected different from the predetermined photo film information.
Accordingly inconsistency between parts constituting a roll photo film, if there is any, can be detected in the course of manufacture.
In another preferred embodiment, a roll photo film producing apparatus includes a support stage for supporting an adhesive tape on a top surface thereof, the adhesive tape having an adhesive surface directed downwards. A plurality of air discharge holes are formed open in the top surface of the support stage, for blowing air toward the adhesive surface of the adhesive tape, to avoid fixing the adhesive tape on the support stage. A suction head sucks up the adhesive tape supported on the support stage. A photo film cutter unit cuts the continuous photo film by a predetermined length, to obtain the photo filmstrip. A head shifter unit shifts the suction head in a substantially horizontal direction from the support stage to the first end of the photo filmstrip while the suction head sucks the adhesive tape, the adhesive tape being attached to the first end of the photo filmstrip. A light-shielding sheet supplier supplies the light-shielding sheet under the photo filmstrip, to lay the first end of the photo filmstrip and the adhesive tape on the light-shielding sheet. A winder unit rotates the spool to wind the photo filmstrip about the core with the light-shielding sheet.
Accordingly the adhesive tape can be attached between the photo filmstrip and the light-shielding sheet with heightened precision.
In another preferred embodiment for producing a roll photo film, there is a conveying path through which a front end of a light-shielding sheet is advanced, the light-shielding sheet having one securing position determined thereon to which a first end of a photo filmstrip is secured. A spool holder supports a spool, the spool having a core to which the front end of the light-shielding sheet from the conveying path is secured. A winder unit rotates the spool on the spool holder in a winding direction, to wind the photo filmstrip and the light-shielding sheet about the core for obtaining the roll photo film. A roll photo film producing apparatus includes a tension applying unit, disposed in the conveying path, for applying back tension of 70-130 grams to the light-shielding sheet, or to the light-shielding sheet and the photo filmstrip, while the spool is rotated in the winding direction.
Furthermore, a pusher unit is disposed with the winder unit, for pushing the light-shielding sheet, or pushing the light-shielding sheet and the photo filmstrip, to the core of the spool with pushing force of 100-300 grams while the spool is rotated in the winding direction.
Accordingly the photo filmstrip or the light-shielding sheet, during operation of rotating the spool, can be wound about the spool without scratches or other failure.
In another preferred embodiment, a roll photo film includes a spool having a cylindrical core, a photo filmstrip having first and second ends, a trailer sheet, having light-shielding ability, for connecting the first end to the core, and a leader sheet, having light-shielding ability, and secured to the second end, the photo filmstrip being wound about the core of the spool with the trailer sheet and the leader sheet. A roll photo film producing apparatus-includes a trailer supply unit for supplying the trailer sheet toward the spool, to mount the trailer sheet on the core. A spool rotating unit rotates the spool in a winding direction to wind the trailer sheet about the core. A photo film supply unit supplies the photo filmstrip toward the spool. A first attacher unit secures the photo filmstrip to the trailer sheet with an adhesive tape, the spool rotating unit being operated thereafter to wind the photo filmstrip about the core. A leader supply unit supplies the leader sheet toward the spool. A second attacher unit secures the leader sheet to the photo filmstrip with an adhesive tape, the spool rotating unit being operated thereafter to wind the leader sheet about the core.
Accordingly the photo filmstrip can be wound reliably with the trailer sheet and the leader sheet.